1. Field of the Invention
The present invention relates to a mixer blade assembly particularly suitable for mixing medium and high viscosity liquids used in pharmaceutical, food, chemical industries and the like.
2. Description of Background Art
It has been known in the prior art to provide a mixer blade assembly as shown in FIG. 14 in which helical ribbon blades b are secured on a rotary shaft a and a bottom impeller c is secured on the bottom end of the rotary shaft a in order to efficiently mix the medium and high viscosity liquid. However, there is a problem in the prior art mixer blade assembly having helical blades in that an insufficiently mixed region having a doughnut-shaped configuration is generated in the liquid when mixing liquids of a certain range of viscosity and therefore good mixing cannot be achieved.